They might not fall in love while you are watching, but they do now when they are at work or teens find romance at the prom.
You're right Saltypaws! I just remembered that my teen Sims went to their prom last night, brother and sister Sims, and he (brother) ended up with a love interest, the girl he danced with. So I quickly checked the sister, coz I've been trying to match her up with a love interest in town, but she came home with nothing, zero love life
I found it interesting and queer, because her brother had the evil trait and she had the friendly trait plus the "attractive" life reward I got for her!
By the way, I've tried this autonomous scheme before, I created a "dormitory" for teens - because I had way too many teen Sims in the neighborhood and I wanted to look after them in one place rather than play many families separately. So I moved in the teen Sims (I started with
a female dormitory) and I put in one adult female Sim to be the caretaker. The caretaker was the one I controlled, her job is to cook group meals and to clean, that was all. I wanted to see what the teen Sims would be upto left on their own in high free will setting. I would say their actions are
a result of their traits and how they were raised as children. I recall the results were so different, some Sims would play all day while some Sims would do their assignments without prompting, some Sims would not bath until they were super smelly, some Sims who were not toilet trained would keep on peeing on the floor (urgh!) Some Sims would learn how to cook for themselves when they were hungry, while some do nothing but complain and just eat junk food when they are super hungry. One Sim almost died because she couldn't make herself get off the exercise machine even when she was starving! In other words, some Sims can handle their own moods/impulses and lives while others cannot (sounds like real life huh?) The game ends when they age into an adult. Try it, it's fun!